Lab talk

Nov 22, 2012

Gold nanoparticles on silica: a metamaterial with catalytic activity

Gold nanoparticles can exhibit excellent catalytic activity, but there are issues to consider such as particle aggregation and re-use. Often these difficulties can be overcome by immobilizing the catalytic nanoparticles on solid supports such as silica. Many groups are involved in synthesizing various kinds of silica-metal-based composite materials. However, the in situ synthesis of gold-nanoparticle-silica composite materials by using only functionalized silica particles without the addition of any external reducing agent can present challenges. To address this, researchers at Kumamoto University in Japan have proposed the following method.

The team has found a facile example of the in situ preparation and fabrication of stable gold nanoparticles on silica in an aqueous medium, by using only lipid-grafted silica particles in HAuCl4 solution without addition of any external reducing agent. The metamaterial particles show high catalytic activity for the reduction of p-nitrophenol to p-aminophenol.

The team used FE-SEM and TEM instruments for observing the silica-lipid-Au conjugate.

About the author

This work was carried out by researchers from the Department of Applied Chemistry and Biochemistry at Kumamoto University, Japan. Dr Sudipta Ray is a postdoctoral research fellow at Kumamoto University in Ihara group, since 2011. Prof. Hirotaka Ihara is head of the supramolecular group and supervised this study. Dr Makoto Takafuji is an associate professor at Kumamoto University. The group’s research focuses on supramolecular nanoarchitecture and photo-energy conversion. This work is funded by the Japan Society for Promotion of Science Research Foundation (JSPS). Further information about the group can be found here.